Individual superatoms are assembled into more complicated nanostructures to diversify their physical properties.Magnetism of assembled superatoms remains,however,ambiguous,particularly in terms of its distance depende...Individual superatoms are assembled into more complicated nanostructures to diversify their physical properties.Magnetism of assembled superatoms remains,however,ambiguous,particularly in terms of its distance dependence.Here,we report density functional theory calculations on the distance-dependent magnetism of transition metal embedded Au_(6)Te_(8)Se_(12)(ATS)superatomic dimers.Among the four considered transition metals,which include V,Cr,Mn and Fe,the Cr-embedded Au_(6)Te_(12)Se_(8)(Cr@ATS)is identified as the most suitable for exploring the inter-superatomic distancedependent magnetism.We thus focused on Cr@ATS superatomic dimers and found an inter-superatomic magnetizationdistance oscillation where three transitions occur for magnetic ordering and/or anisotropy at different inter-superatomic distances.As the inter-superatomic distance elongates,a ferromagnetism(FM)-to-antiferromagnetic(AFM)transition and a sequential AFM-to-FM transition occur,ascribed to competitions among Pauli repulsion and kinetic-energy-gains in formed inter-superatomic Cr-Au-Au-Cr covalent bonds and Te-Te quasi-covalent bonds.For the third transition,in-plane electronic hybridization contributes to the stabilization of the AFM configuration.This work unveils two mechanisms for tuning magnetism through non-covalent interactions and provides a strategy for manipulating magnetism in superatomic assemblies.展开更多
Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchan...Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchange coupling.Here we propose a general strategy of self-intercalation to achieve enhanced ferromagnetism in bilayer CrI 3.We show that filling either Cr or I atoms into the van der Waals gap of stacked and twisted CrI 3 bilayers can induce the double exchange effect and significantly strengthen the interlayer ferromagnetic coupling.According to our first-principles calculations,the intercalated native atoms act as covalent bridge between two CrI 3 layers and lead to discrepant oxidation states for the Cr atoms.These theoretical results offer a facile route to achieve high-Curie-temperature 2D magnets for device implementation.展开更多
基金financial support from the National Key R&D Program of China(Grant No.2023YFA1406500)the National Natural Science Foundation of China(Grant Nos.11974422,12104504,and 12204534)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China(Grant No.22XNKJ30)。
文摘Individual superatoms are assembled into more complicated nanostructures to diversify their physical properties.Magnetism of assembled superatoms remains,however,ambiguous,particularly in terms of its distance dependence.Here,we report density functional theory calculations on the distance-dependent magnetism of transition metal embedded Au_(6)Te_(8)Se_(12)(ATS)superatomic dimers.Among the four considered transition metals,which include V,Cr,Mn and Fe,the Cr-embedded Au_(6)Te_(12)Se_(8)(Cr@ATS)is identified as the most suitable for exploring the inter-superatomic distancedependent magnetism.We thus focused on Cr@ATS superatomic dimers and found an inter-superatomic magnetizationdistance oscillation where three transitions occur for magnetic ordering and/or anisotropy at different inter-superatomic distances.As the inter-superatomic distance elongates,a ferromagnetism(FM)-to-antiferromagnetic(AFM)transition and a sequential AFM-to-FM transition occur,ascribed to competitions among Pauli repulsion and kinetic-energy-gains in formed inter-superatomic Cr-Au-Au-Cr covalent bonds and Te-Te quasi-covalent bonds.For the third transition,in-plane electronic hybridization contributes to the stabilization of the AFM configuration.This work unveils two mechanisms for tuning magnetism through non-covalent interactions and provides a strategy for manipulating magnetism in superatomic assemblies.
基金supported by the National Natural Science Foundation of China(11504041)the Fundamental Research Funds for the Central Universities of China(DUT16LAB01,DUT17LAB19)the Supercomputing Center of Dalian University of Technology,China~~
基金Supported by the National Natural Science Foundation of China(Grant Nos.11974068 and 11874097)the China Postdoctoral Science Foundation(Grant Nos.BX20190052 and 2020M670739)the Fundamental Research Funds for the Central Universities of China(Grant Nos.DUT20LAB110 and DUT19LK12)
文摘Two-dimensional(2D)ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications.CrI 3 is a rising star of intrinsic 2D ferromagnets,however,it suffers from weak exchange coupling.Here we propose a general strategy of self-intercalation to achieve enhanced ferromagnetism in bilayer CrI 3.We show that filling either Cr or I atoms into the van der Waals gap of stacked and twisted CrI 3 bilayers can induce the double exchange effect and significantly strengthen the interlayer ferromagnetic coupling.According to our first-principles calculations,the intercalated native atoms act as covalent bridge between two CrI 3 layers and lead to discrepant oxidation states for the Cr atoms.These theoretical results offer a facile route to achieve high-Curie-temperature 2D magnets for device implementation.
